This invention relates to an improved arrangement for mounting a getter device in an electron tube, particularly a television picture tube.
Getter devices are well known in the art, see for example U.S. Pat. Nos. 2,822,080; 3,207,294; 3,207,295 and 3,211,280. When getter devices are used in television picture tubes it is common practice to mount them in the so called antenna position, see U.S. Pat. No. 4,182,974. The getter device has also been attached to the frame of the shadow mask in colour television picture tubes, see U.S. Pat. No. 3,792,300.
Whatever their mounting position, use is frequently made of a tab which forms part of the getter device structure. The tab then allows the getter device to be held in its required position within the electron tube such as, for instance, by welding the tab to one end of an antenna spring within a television picture tube. Unfortunately, when the getter device is heated by induction from a R.F. coil positioned outside the tube, the tab is also heated and tends to soften and bend causing the getter container to move out of its proper position with all the resulting disadvantages and defects as described thoroughly in U.S. Pat. No. 3,558,961. This U.S. patent itself discloses an attempt to overcome the positioning problems that occur during getter device heating but, unfortunately, this attempt requires additional manufacturing steps to be performed on the antenna spring. The spring has also to be cut to shape from a strip much wider than that required for the actual spring width with the subsequent creation of large amounts of scrap material. It would, therefore, be advantageous if the tab of the getter device could itself be rendered more rigid.
Therefore, it is the primary object of this invention to provide an improved support tab member integrally formed with a getter metal vapour releasing material assembly.
It is another object of the present invention to provide an improved support tab member that ensures proper positioning of the getter device during and after heating the device.